The present disclosure relates generally to the field of brake power generating apparatuses or brake booster apparatuses. Specifically, an electrohydraulic brake power generating apparatus for a motor vehicle brake system is described.
Various electrohydraulic brake systems are known from the prior art and disclosed, for example, in WO 2012/062393 A1 and in WO 2012/152352 A1. These motor vehicle brake systems work by the “brake-by-wire” principle. This means that a hydraulic pressure is built up at the wheel brakes independently of the foot force. The electrohydraulic brake systems taught therein have various brake circuits, which are controllable by means of hydraulic fluid, or a hydraulic fluid pressure. Known hydraulic pressure generators further comprise a cylinder-piston device for generating hydraulic pressure and an electromechanical actuator which acts on the piston of the cylinder-piston device. The electromechanical actuator is arranged downstream of the cylinder-piston device and is coupled directly with the piston of the cylinder-piston device. The piston can thus be operated directly via the actuator, whereby a hydraulic pressure can be built up at the wheel brakes independently of the foot force. The cylinder-piston device is further coupled via a power transmission device with a pedal interface arranged downstream of the cylinder-piston device and the electromechanical actuator. In the case of emergency operation of the brake system, the power transmission device allows the cylinder-piston device to be coupled mechanically with the brake pedal interface so that the piston of the cylinder-piston device can be operated by means of the foot force present at the pedal interface (push-through operation).
WO 2014/95 286 A1 describes an electrohydraulic vehicle brake system having two actuators which are so configured that they are able to actuate a main cylinder piston independently of one another (separately or together). A decoupling device is functionally provided between a brake pedal and a power transmission element. The decoupling device allows the brake pedal to be selectively uncoupled from the piston arrangement in the main cylinder. Within the scope of normal service braking, both the decoupling device and the simulation device are activated, while they are deactivated in emergency operation.
DE 10 2011 016 940 A1 describes a hydraulic brake system with brake-by-wire activation, in which at least one operating piston is displaceably guided in a hydraulic operating piston chamber and can be shut off hydraulically by means of an operating piston valve arrangement in order to block the at least one operating piston. The operating piston valve arrangement is closed in a first operating position, which is present in the case of a proper operating condition of the brake system, on operation of the force input member to shut off the hydraulic operating piston chamber, and is open in a second operating position, which is present in the case of an improper operating condition of the brake system, on operation of the power input member to release the hydraulic operating piston chamber.
An electrohydraulic brake power generating apparatus for electrohydraulic motor vehicle brake systems is to be provided. The electrohydraulic brake power generating apparatuses are further to occupy as little installation space as possible in the motor vehicle and be inexpensive to produce.